In the oil and gas industry it is conventional to mount a rotating blowout preventer or rotating flow control diverter at a top of a blowout preventer (BOP) stack beneath a drilling floor of a drilling rig while drilling for oil, gas or coal bed methane. Existing rotating flow control diverters serve to seal a pipe that is being moved in and out of a wellbore while allowing the pipe to rotate in the wellbore. Existing rotating flow control diverter may also be used to contain or divert fluids such as drilling mud, produced fluids, and surface injected air or gas into a recovery line.
Existing rotating flow control diverters consist of rubber strippers or sealing elements and an associated hollow shaft that rotates with the drill string within a robust housing. Rotation of the strippers and the associated hollow shaft may be facilitated by a bearing assembly typically having an inner race that rotates with the drill string and an outer race that remains stationary with the housing. The bearing assembly is isolated from fluids and/or gases in the wellbore by seals.
However, existing stripper elements are often compromised or damaged from a tool joint passing through the stripper element arranged with the rotating flow control diverter. Stripping element failure is one manner in which a rotating flow control diverter may encounter mechanical problems. For example, a stripping element may be compromised or damaged causing the stripping element to fail to seal a pipe arranged in a wellbore because a tool joint passing through the stripping element may produce sufficient pressure on the stripping element, and/or cause expansion of the stripping element, to invert and/or tear the stripping element. For example, a tool joint passing through an elastomer arranged on a stripping element metal sub may cause the elastomer to fail by inverting the elastomer or tearing the elastomer. A failure of a stripper element may cause downtime in a drilling operation. Further, it is imperative that the stripper elements are robust and reliable to safeguard workers operating in the vicinity of rotating flow control diverters. It is therefore desirable that a rotating flow controller diverter be designed with components that function in a trouble free manner, and that are as durable as other associated drilling components.
Accordingly, there remains a need in the art for improved stripper elements that reduce or prevent failure of rotating flow control diverters to reduce downtime in drilling operations and safeguard workers operating in the vicinity of the rotating flow control diverters. It is therefore desirable that a rotating flow controller diverter be designed with components that function in a trouble free manner, and that are as durable as other associated drilling components.